Spindle for spinning or twisting machines



Oct. 22, 11968 H. STAHLECKER 3,406,512

SPINDLE FOR SPINNING OR TWISTING MACHINES Filed March 14. 1967' 3 Sheets-Sheet 1 INVENTOR HANS STAHLECKER BY Z ATTORNEYS Get. 22, 1968 H. sTAHLEcKEP. 3,406,512

SPINDLE FOR SPINNING OR TWISTING MACHINES Filed March 14. 1967 5 Sheets-Sheet 2 Oct. 22, 1968 H. STAHLECKER 3,406,512

SPINDLE FOR SPINNING OR TWISTING MACHINES Filed March 14. 1967 5 Sheets-Sheet 5 United States Patent 3,406,512 SPINDLE FOR SPINNING 0R TWISTING MACHINES Hans Stahlecker, Snssen, Wurttemberg, Germany, assignor to Spindelfabrik Sussen, Schurr, Stahlecker & Grill G.m.b.H., Sussen, Wurttemberg, Germany Filed Mar. 14, 1967, Ser. No. 623,006 Claims priority, applicatiog gtgmany, Dec. 27, 1966,

. 0 18 Claims. (Cl. 57-88) ABSTRACT OF THE DISCLOSURE A spindle with spindle brake which acts upon the wharve on the center shaft and may be removably secured to the spindle by a supporting member which includes a bifurcated plate which is inserted from one side into an annular groove or a pair of opposite transverse grooves in the outer surface of the bearing housing surrounding the center shaft.

Background of the invention The present invention relates to a spindle for a spinning or twisting machine, which is provided with a brake comprising a pair of brake levers which engage radially upon the wharve of the center shaft of the spindle and are mounted together with their control means on a brake support which is connected to the spindles.

There are various constructions of spindles of the above-mentioned type known in the prior art. In some of these spindles, as disclosed, for example, in the US. Patents Nos. 3,063,230, 2,770,092, and 2,449,773, the radially acting brake means are mounted on the spindle flange which is provided with special arms and/or supporting projections.

These constructions have the serious disadvantage that the spindle flanges which are cast integrally with the spindle bearing housings have a complicated shape which renders the manufacture of the spindles very diflicult and prevents these housings from being universally applied to spindles of different constructions.

In other known spindle constructions as disclosed, for example, in the US. Patent No. 3,122,875 and the German published patent application No. 1,186,787, the brake supports are provided with bores through which the bearing housings are inserted. When the spindle nut is then tightened, the brake support is clamped tightly between the spindle flange and the spindle rail. These spindle constructions have the disadvantage that the brake must be installed together with the spindle and that therefore it cannot be removed except when the spindle is also removed. When the brake is then again installed, it becomes necessary to recenter the spindle. Another disadvantage of these spindle constructions is also the fact that when the spindle is loosened for being centered, the brake support is also loosened and must be shifted together with the spindle.

Furthermore, the fact that the use of such a brake requires the spindle flange to be located at a higher level within the bearing housing than when no brake is provided is also economically of disadvantage insofar as the manufacture, storage, and replacement of such spindles is concerned. The conventional spindles in which the brake support is partly inserted from above into the wharve and is clamped together with the wharve flange by means of a screw which is in an inclined position on the brake support have the further disadvantage that they are of considerable height and width and that therefore their manufacture is also expensive.

3,406,512 Patented Oct. 22, 1968 Summary of the invention It is an object of the present invention to provide a spindle brake with a brake support which eliminates the aforementioned disadvantages, is of a simple construction and applicable as universally as possible to different kinds of spindles, and is of a low height. Another object of the invention is to mount the brake in a manner so as to permit the bearing housing of the spindle and the spindle flange to be made of the simplest possible construction and the spindle to be secured in different manners to the spindle rail. A further object of the invention is to design the spindle brake so as to form a unit which is as self-enclosed as possible and adapted to be easily cleaned.

These objects are attained according to the invention by providing the brake support with a bifurcated plate, the arms of which are adapted to be inserted from one side into transverse grooves in the outer surface of the bearing housing and are held in radial directions in these grooves at least at two points. These transverse grooves may be made of a very narrow width, especially if the bifurcated plate is made of high-strength or hardened sheet steel. Since the contact width of the arms of such a plate and thus also the depth of the grooves may be made very small, it is easily possible to find suflicient space on the housing or on the wharve flange for providing such grooves and they may also be very easily produced.

'Such grooves may be formed by cutting two individual parallel grooves, for example, into the spindle flange if for certain reasons this flange should be made very narrow in the longitudinal direction of the machine and must therefore be provided with plane parallel surfaces. It is, however, especially of advantage to provide the transverse grooves for receiving the bifurcated plate in the bearing housing in the form of a common annular groove. Such grooves may be cut into the tubular hearing housing of the spindle or directly into the wharve flange. In the latter case, the wharve flange may be a simple annular flange which may be integral with the bearing housing or secured thereto, for example, by being welded or screwed thereto. In certain cases, for example, when the collar bearing of the spindle is provided with a closure cap or when for other reasons additional spindle parts are provided adjacent to the collar bearing, it may be of advantage if one shoulder of the transverse grooves on the bearing housing, which are preferably combined in the form of a common annular groove, is formed by the outer surface of a special part which is provided on the bearing housing and consist, for example, of a closure cap for the collar bearing. For securing the bifurcated plate in a fixed position, it is another very advantageous feature of the invention to make the arms of the bifurcated plate which are inserted into the transverse grooves of the bearing housing of a radially resilient construction so as to exert a resilient clamping pressure upon the bottom of the opposite grooves. If the brake is made of such a construction, it may be easily installed and removed at any time, and its installation may thus be carried out, for example, after the spindle has been centered. Since the spindle brakes may therefore be supplied separately from the bearing housings, the latter may also be more easily packed, shipped, and installed.

In certain cases it may also be advisable to secure the ends of the arms of the bifurcated plate within the transverse grooves by permanently deforming these ends after being inserted. Although the bifurcated plate may in this case not be hardened or entirely hardened and must therefore have a greater thickness than a hardened plate, it has the advantage that the brake after being installed on the spindle can no longer be removed therefrom by an unauthorized person. Such brakes which after being installed are permanently secured to the spindles or can be removed therefrom only with difficulty are very desired by the managers of many spinning mills.

Another preferred feature of the invention consists in designing the bifurcated plate so that the ends of its arms resiliently engage in radial directions upon the bottom of the transverse grooves or the annular groove at points behind the central longitudinal plane of the bearing housing so that a force component is thereby produced which presses the bifurcated plate into the groove in the direction of the transverse central plane and thus produces a perfect three-point contact of the bifurcated plate with the bearing housing. There is thus no danger that the connection of the brake to the housing will be loosened and the tolerances of manufacture of the annular groove and the bifurcated plate do not need to be made as small as it would otherwise be necessary. A very advantageous embodiment of the invention consists in making the brake support and the bifurcated plate integral with each other. Special securing means which might loosen are then not required which also facilitates the manufacture of the brake.

Another feature of the invention consists in making the brake support of a U-shaped frame of sheet steel, the lower arm of which is extended so as to form the bifurcated plate. Such a frame may be made of a very solid construction, requires very little space especially in height, and easily accommodates the other parts of the brake. According to a further feature of the invention, the two brake levers are for this purpose inserted between the upper and lower arms of the frame and pivotably mounted on the central web of the frame, and in their inactive position, they are pressed by a common spring against an eccentric which is rotatably mounted on the two arms of the frame and carries a control lever which may be located either above or below the frame. The two brake levers are also preferably designed so as to close the lateral openings of the U-shaped frame so as to form a closed box.

In order to prevent the brake support from turning in a radial direction, it is a further feature of the invention to provide the bifurcated plate with a projection which engages into a recess in the bearing housing and preferably in the bottom of the annular groove which forms the opposite transverse grooves. Another feature which is of considerable advantage consists in providing at least one of the two brake levers with a safety hook which projects over one of the flanges of the wharve and thereby prevents the center shaft from being unintentionally withdrawn in the upward direction. This safety hook is preferably made integral with the brake lever, especially if the latter is made of sheet steel, or with a separate brake shoe which may be provided on the brake lever. In order to withdraw the center shaft, it is then necessary to press the brake lever together with the safety hook outwardly to such an extent that the hook will no longer engage over the wharve flange. This may be done either by hand or by means of a special tool. It may also be done in a very simple and effective manner by providing the eccentric for pivoting the brake levers with a cam surface which is adapted to pivot the brake lever carrying the safety hook so far radially toward the outside from its neutral position that the wharve with the center shaft may be upwardly withdrawn.

If a spindle is to be provided with a separate safety hook which is not connected to the brake, the transverse grooves which are preferably combined into a single annular groove for receiving the bifurcated plate of the brake support may be provided on the spindle flange, while the neck of the housing above the spindle flange may be provided with another annular groove into which a bifurcated plate engages which serves as a support for the safety hook of the spindle.

The various features and advantages of the present invention will become more clearly apparent fromthe following detailed description thereof which is to be read with reference to the accompanying drawings, in which:

FIGURE 1 shows a side view, partly in cross section which is taken along the line 1-1 of FIGURE 2, of a wharve brake which is secured to a spindle and brake support of which consists of a U-shaped bracket of sheet steel, the lower arm of which is extended so as to form a bifurcated plate which engages radially into an annular groove in the spindle flange;

FIGURE 2 shows a top view of the brake according to FIGURE 1, as seen in a cross section which is taken along the line IIII of FIGURE 1;

FIGURE 3 shows a top view of the bracket according to FIGURES 1 and 2 which engages into the annular groove of the spindle flange;

FIGURE 4 shows a side view of a part of the brake according to FIGURE 1, but with a different control handle;

FIGURE 5 shows a side view of a brake support in the form of a U-shaped bracket similar to that as shown in FIGURE 3, but with a separate bifurcated plate riveted thereon;

FIGURE 6 shows a top view of a bifurcated plate which engages into an annular groove similarly as shown in FIGURE 3 but wherein the contact surfaces of the ends of the arms of this plate are disposed symmetrically to the central longitudinal plane of the annular groove;

FIGURE 7 shows a top view of a bifurcated plate engaging into an annular groove similarly as shown in FIGURE 3, but wherein the ends of the arms of this plate are permanently deformed;

FIGURE 8 shows a side view of a brake which is similar to that as shown in FIGURE 1, but provided with brake levers made of sheet steel and with a safety hook on one of the brake levers;

FIGURE 9 shows a top view of the brake according to FIGURE 8 as seen in a cross section which is taken along the line IX-IX of FIGURE 8;

FIGURE 10 shows a cross section which is taken along the line XX of FIGURE 8 of the safety hook in its operative position above the wharve flange;

FIGURE 11 shows a cross section of a safety hook similar to that as shown in FIGURE 8 but mounted on a brake shoe;

FIGURE 12 shows a top view of an eccentric for pivoting the brake levers apart, which is similar to the eccentric according to FIGURE 9 but provided with a special cam surface for operating the brake lever which carries the safety hook;

FIGURE 13 shows a side view, partly in cross section, of a brake which is secured within the annular groove of the spindle fiange in a similar manner as shown in FIG- URE 1 in combination with a supporting plate for a safety hook which is secured in a further annular groove of the bearing housing;

FIGURE 14 shows a top view of a bearing housing with a spindle flange which is provided with plane parallel surfaces into which transverse grooves are cut for receiving the bifurcated plate of the brake support;

FIGURE 15 shows a side view of a wharve brake which is secured by means of a bifurcated plate in an annular groove of the tubular bearing housing which is not provided with a spindle flange but is clamped radially in the bore of the spindle rail by means of a yoke-shaped clamping strap; while FIGURE 16 shows a side view, partly in section, of a wharve brake which is secured by means of a bifurcated plate in an annular groove of the spindle flange and wherein the upper shoulder of the annular groove is formed by a closure cap.

As illustrated in FIGURES 1 and 2 of the drawings, the spindle rail 1 is provided with bores 1a in which the bearing housing 2 of the various spindles are mounted with a small amount of play which is necessary for accurately centering the spindles. For securing each hearing house 2 to the spindle rail 1, the spindle flange 2a which is integral with the bearing housing 2 is clamped in the axial direction to the upper flange of the spindle rail 1 by means of the spindle nut 23. The center shaft 4 carries the spindle wharve 4a which is driven by a belt. The spindle flange 2a is provided with an annular groove 2b in its peripheral surface. The spindle brake comprises a brake support 5 in the form of a U-shaped bracket 5 of bent sheet steel, the lower arm 5a of which extends beyond the upper arm 5b and forms a bifurcated plate 6 with two fork arms 6a and 6b which are resilient in radial directions and are inserted from one side into the annular groove 2b in the spindle flange 2a so that, as indicated in FIGURE 3, the ends 6a and 6b of the fork arms press radially upon the bottom of groove 2b.

As illustrated particularly in FIGURE 3, plate 6 is additionally provided between the two fork arms 6 and 6b with a pair of surfaces 6c and 60 which likewise engage upon the bottom of the annular groove 2b. Since the contact surfaces 6a and 6b of the fork ends press resiliently in the radial direction into groove 2b at points behind the ecntral longitudinal plane E3-E3, of the bearing housing, they produce force components which press the surfaces 60 and 60 into the annular groove 2b. Between the surfaces 6c and 60 a safety projection 60 is provided which engages into a bore 2d in the bottom of groove 2b in wharve 4a. The annular groove 2b has a width substantially corresponding to the thickness of plate 6 so that the latter is slidable laterally into this groove and will be properly secured in radial as well as axial directions. The central web 5c of the brake supporting bracket 5 supports the rear ends of two brake levers 7a and 7b which consist of plastic, for example, polyamide, and are for this purpose provided with notches 7a and 7b as shown in FIGURE 2. Brake levers 7a and 7b are resiliently pressed against the curved cam surfaces 90 and 9b of an eccentric 9 by the ends of a leaf spring 8 which is bent back and forth so as to have a wavy shape and thus a very good spring characteristic. The eccentric 9 which is integral with the cam surfaces 9a and 9b and a control handle 9c and consists of plastic is pivotably mounted within the arms 5a and 5b of bracket 5. The rear ends of brake levers 7a and 7b carry brake shoes 7e and 7 which, when the brake is not applied and thus in the position as illustrated, are spaced at a small radial distance from the wharve flange 4b. If the control handle 9c is turned in the clockwise direction to the position as indicated in FIGURE 2 in dot-and-dash lines, brake levers 7a and 7b will be pivoted by the tension of spring 8 relative to each other about their pivot points 7a; and 7 b on the opposite ends of the central web 5c of bracket 5 until the brake shoes 7e and 7f engage upon the wharve flange 4b and thereby stop the rotation of the spindle. The projections 7g and 7h on brake levers 7a and 7b facilitate the installation of the brake levers and spring 8 within the braket 5 since before being installed they are forced apart by the tension of spring 8 and are thus held together like the arms of a clothes clamp. The eccentric 9 may be inserted from below into bracket 5 since its bearing flange 9d and the corresponding bore in the lower arm 5a of bracket 5 have a diameter larger than the maximum diameter of the eccentric 9. A lock washer 9e secures the eccentric 9 within bracket 5. The minimum diameter of the eccentric is made of such a size that a proper braking action will occur even if the brake shoes 72 and 71'' are worn considerably.

FIGURE 4 shows a bracket 45 and brake levers 47a and 47b which are of the same shape as the bracket 5 and brake levers 7a and 7b in FIGURES 1 and 2 and it illustrates the manner in which bracket 45 is laterally completely enclosed by brake levers 47 and 47b. The control handle 49c is located above bracket 45 and integral with the eccentric 49 which is inserted from above and locked at its lower end by a lock washer 49e. The

eccentric 49 with the control handle 49c on its upper end as shown in FIGURE 4 may be easily exchanged for an eccentric 9 with a control handle 90 on its lower end, as shown in FIGURE 1.

The brake support 55 according to FIGURE 5 likewise consists of a U-shaped bracket of sheet steel, the lower arm 55a of which is, however, riveted or screwed upon a separate bifurcated plate 56. The brake which is mounted in such a brake support may be employed in association with brake grooves of different diameters, for example, in a spindle flange as shown in FIGURE 1 or in a tubular housing as shown in FIGURE 15, by merely securing different brake plates 56 to the lower arm 55a of bracket 55.

According to FIGURE 6, the ends of the fork arms of plate 66 are provided with surfaces 66:1 and 66b which contrary to those in FIGURE 3 are not located at the rear of the central plane E6E6 but substantially cen trally thereto. The central position of the brake is determined by the arcuate contact surfaces 6611 and 66b. A third contact surface is in this case not required.

The bifurcated plate 76 according to FIGURE 7 is provided with concave surfaces 760 and 760 which are separated from each other by a convex projection 760;; and engage upon the bottom of the annular groove 72b after the originally straight ends 7641 and 76b of the fork arms of plate 76, as indicated in FIGURE 7 in dotted lines, have been inserted into groove 72b. By means of a special tool, these ends 7611 and 7-6b are then bent toward each other so as likewise to engage upon the bottom of groove 72b. In order to prevent the bifurcated plate 76 from turning, the convex projection 760 on this plate engages into a concave recess 72d which is milled into the bottom of groove 72b. Plate 72 may also be prevented from turning by peening the fork ends 76:1 and 76b together with the walls of groove 72b when these ends are bent toward each other. In this event, the convex projection 760 on plate 72 and the milled recess 72d in groove 72b may be omitted.

According to FIGURES 8 and 9, the brake support again consists of a U-shaped bracket of sheet steel, but the lower arm 85a of this bracket is integral with the bifurcated plate 86 which is inserted into an annular groove 82b in the spindle flange and prevented from turning relative thereto in a similar manner as shown in FIG- UR'E 3. The brake levers 87a and 87b likewise consist of sheet steel and their outer ends are supported on the slightly recessed end surfaces 850 and 85o of the central web 85c of brake support 85. These end surfaces 850 and 850 are further provided with guide projections 85c for the brake levers 87a and 87b which are provided with recesses for receiving these projections. A coil spring 88 is inserted between the ends of brake levers 87a and 87b and its bent-over ends 88a engage into grooves 87h in these levers and thereby press the contact plates 87a and 87b on the levers into engagement woth the eccentric 89 when the brake is not applied. The eccentric 89 is keyed on its shaft 89a which is integral with the control handle 89c and mounted on the brake support 85 in a similar manner as shown in FIGURE 1. The inner end of brake lever 87b which carries the brake shoe 87f is upwardly extended to form a safety hook 87g which projects slightly over the wharve flange 84b, as shown in FIGURE 10. If the rotary part of the spindle is to be pulled out of the bearing housing, brake lever 87b is pressed outwardly by means of a special tool until hook 87g no longer projects over the wharve flange 84b. FIG- URES 8 and 9 also illustrate that the brake levers cover the sides of the brake support 85 completely so that the brake forms a closed box from which only the control handle 89c and the rear parts of the brake levers project.

A modification of the safety hook according to FIG- URE 10 is illustrated in FIGURE 11 in which a brake shoe 117 which is riveted to the brake lever 117b is upwardly extended to form a safety hook 117g.

FIGURE 12 illustrates an eccentric 129 which is mounted on its shaft 89a in place of an eccentric 89 with two equal cam surfaces as shown. in FIGURE 9 and is provided at the right side of the cam surface 1290 with an additional cam projection 1290! so that, when the control handle 890 which is shown in FIGURE 12 in solid lines in the loose position of the brake is pivoted to the dotted-line position 890 the brake 87b as shown in FIG- URE 9 will be pivoted so far outwardly that its hook 87g will release the wharve and permit it to be withdrawn. The eccentrics 89 and 129 according to FIGURES 9 and 12 may be exchanged from each other and also be reversed in position on the shaft 89a upon which one or the other is plugged, if the control handle 890 is to be pivoted in the opposite direction.

According to FIGURE 13, the spindle flange 132a is screwed on and caulked together with the tubular housing 132 by the application of pressure and heat which is generated by electrodes, for which purpose the recess 1322 on the spindle flange is required. In the annular groove 132b of the flange a brake is mounted similar to that as shown in FIGURES 8 and 9, but without a safety hook 87g. Directly adjacent to the upper end surface of the spindle flange, the housing 132 is provided with an annular groove 132s in which a bifurcated plate 130 similar to that as shown in FIGURES 3, 6 or 7 is secured. This plate 130 is integral with an upwardly projecting hook holder 13011 which is provided with a slot 13% and in the eye 1300 of which a safety hook 130d is pivotably mounted in a conventional manner. Hook 130d which is shown in its operative position projects over the wharve flange 13412 and may be pivoted by hand in a counterclockwise direction when the center shaft is to be withdrawn in the upward direction. Such brakes which are connected to the bearing housings of the spindles by means of their bifurcated plates and are provided with safety hooks may be combined in many different manners with spindles of different dimensions and may be easily installed and removed, if necessary. This possibility may be further enlarged by providing the flange in addition to the bore 132d into which the safety projection of the bifurcated plate extends with two further bores 132f in diametrically opposite positions for receiving the pivot pin of one of the conventional bracket-shaped wharve brakes which are operated by hand or a knee so as to act upon one side of the wharve. Spindles which are provided with such a universally applicable flange and with an annular groove 132c in the tubular housing may be equipped at any time either by the manufacturer or the purchaser of the spindles with a simple pressing brake of a conventional type or with a brake according to the invention. The arrangement of the safety book may then also be modified as desired.

According to FIGURE 14, the bifurcated plate 146 has a pair of fork arms with plane parallel contact surfaces 14642 and 146b which engage into corresponding grooves l42b in the parallel sides of the spindle flange 142a. The projections 1460 on the ends of the fork arms prevent the bifurcated plate from being unintentionally withdrawn from the grooves of the spindle flange. The bifurcated plate 146 is to be screwed or riveted to the brake support in a similar manner as shown in FIGURE it may, however, also be integral with the brake support.

According to FIGURE 15, the flangeless bearing housing 152 is secured in the spindle rail 151 by a clamping bracket 153, that is, by pressing the housing radially against the wall of the spindle bore 151a. The tension which is required for this purpose is produced by the setscrew 151b which is screwed into the non-rotatable nut 1510. The yoke-shaped brake support 155 for the wharve brake is held by the bifurcated plate 156 in the annular groove 15212 of the bearing housing 152 and it is prevented from turning by the projection 156c which engages into a slot 153a in the clamping bracket 153. In place of the projection 1560' it is also possible to use a locking screw which is advisable, for example, if the distance between the annular groove 15212 and bracket 153 is considerably larger than shown in FIGURE 15.

The spindle flange 162a according to FIGURE 16 is provided with an upper shoulder 16212 from which an annular, axially projecting flange 16212 extends which is provided with a conical bore and an outer screw thread. The collar bearing 1640 in the form of a ball bearing which is mounted on the center shaft 164 is surrounded by an elastic sleeve 164d which is compressed by a clo sure cap 1620 which is screwed cpon the annular flange 16212 and maintains the collar bearing 1640 including the center shaft 164 in the operative position in which the lower end surface 1620 of cap 1620 together with the shoulder 16212 and the lower part the annular flange 16212 form an annular groove 162b in which the bifurcated plate 166 is held which is integral with the yokeshaped brake support 165. Cap 1620 as illustrated in FIG- URE 16 as being of such dimensions that the Width of the annular groove 162b permits the bifurcated plate 166 to be inserted when cap 1620 is firmly screwed on the flange 162b and the inner bottom of the cap then engages upon the upper end surface of flange 162b Cap 162c may, however, also be made of such dimensions that, when screwed tightly upon flange 16212 its bottom will be spaced slightly from the end of this flange, while its lower surface 1620 engages upon the bifurcated plate 166. If the center shaft 164 is to be removed from the bearing housing, cap 1620 is screwed out of the annular flange 162b by means of a special tool and then pulled together with the center shaft and the ball bearing out of the annular flange 162b after the brake has been pulled laterally out of the annular groove 1621). The spindle according to FIGURE 16 as well as any of those as shown in the other drawings may also be employed in the machine without a brake and without requiring any structural changes.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.

Having thus fully described my invention, what I claim is:

1. A spindle for a spinning or twisting machine having a center shaft, a wharve secured to said shaft, a bearing housing surrounding said shaft and adapted to be secured to the spindle rail of said machine and having opposite transverse grooves in its outer surface, a brake support, a bifurcated plate secured to said brake support and having arms adapted to be inserted from one side into said grooves and engaging at least at two points in radial directions upon the bottom of said grooves so as to secure said brake support to said bearing housing, and a brake comprising a pair of brake levers each pivotably mounted at One end on said brake support, the other ends of said levers being adapted to act in radial directions upon said wharve at substantially diametrically opposite points thereof, and means mounted on said brake support for pivoting said levers.

2. A spindle as defined in claim 1, wherein said transverse grooves are combined so as to form a single annular groove.

3. A spindle as defined in claim 2, further comprising a separate part secured to the upper end of said bearing housing and forming an annular outer shoulder, said housing having a part near its upper end also forming an annular outer shoulder, said shoulder being spaced from each other at a distance substantially equal to the thickness of the arms of said bifurcated plate and together forming said annular groove having a bottom formed by at least one of said parts.

4. A spindle as defined in claim 3, wherein said housing has an upper part of a smaller diameter than the adjacent lower part and forming an outer annular shoulder on the end of said lower part, said separate part forming a caplike member covering the upper end of said housing and adapted to be secured to said upper part of said housing and having a central aperture for inserting said center shaft, and an annular outwardly projecting flange on the lower end of said caplike member spaced from said shoulder when said member is secured to said housing so as to form said annular groove.

5. A spindle as define in claim 1, wherein said arms of said bifurcated plate are adapted to press resiliently upon the bottom of said grooves.

6. A spindle as defined in claim 1, wherein the ends of said arms of said bifurcated plate after being inserted into said grooves are permanently deformed so as to be secured in a fixed position in said grooves.

7. A spindle as defined in claim 2, wherein the ends of said arms of said bifurcated plate after being inserted into said annular groove engage resiliently upon the bottom of said groove at points behind the central longitudinal plane of said housing, as seen from the side from which said arms are inserted, and thereby produce a force component which presses the main part of said bifurcated plate in the direction toward said central plane so as to maintain said arms in a fixed position in said groove.

8. A spindle as defined in claim 1, wherein said brake support and said bifurcated plate are integral with each other.

9. A spindle as defined in claim 8, wherein said brake support forms a substantially U-shaped member of sheet steel having a lower arm of a greater length than its upper arm and forming said bifurcated plate.

10. A spindle as defined in claim 9, wherein the rear ends of said brake levers are pivotally mounted on the central web of said U-shaped member, and further comprising an eccentric disposed between and rotatably mounted on the arms of said U-shaped member and engaging with the inner sides of said levers intermediate their ends, a control handle secured to one end of said eccentric for turning the same and for thereby pivoting said brake levers in opposite directions to each other, and a spring member between the arms of said U-shaped member and acting upon said brake levers so as to maintain the same in engagement with said eccentric.

11. A spindle as defined in claim 10, wherein said brake levers substantially close the open lateral sides of said U-shaped member.

12. A spindle as defined in claim 2, wherein said housing has a recess in the bottom of said groove, said bifurcated plate having a projection on its main part between its arms, said projection engaging into said recess so as to prevent said plate from turning relative to said housmg.

13. A spindle as defined in claim 1, further comprising a safety hook mounted on at least one of said brake levers and adapted to engage over a flange of said wharve so as to prevent said wharve together with said center shaft from being unintentionally withdrawn in the upward direction.

14. A spindle as defined in claim 13, wherein said safety hook is integral with said brake lever.

15. A spindle as defined in claim 13, further comprising a brake shoe on one end of each brake lever, said safety hook being secured to one of said brake shoes.

16. A spindle as defined in claim 10, further comprising a safety hook mounted on at least one of said brake levers and adapted to engage radially inwardly over a flange of said wharve so as to prevent said wharve together with said center shaft from being unintentionally withdrawn in the upward direction, said eccentric having an additional cam projection adapted when said eccentric is turned by said control handle beyond a certain position in which said brake lever is disengaged from said wharve, said cam projection will pivot said lever so far radially outwardly from said wharve that said wharve together with said shaft may be withdrawn.

17. A spindle as defined in claim 2, further comprising a spindle flange secured to said bearing housing, said annular groove being provided in the outer peripheral surface of said spindle flange, said housing having another annular groove above said spindle flange, and a plate having a pair of arms at one end thereof engaging into said other annular groove and held in a fixed position therein, and a safety hook on the other end of said last plate adapted to engage radially inwardly over a flange of said wharve so as to prevent said wharve together with said center shaft from being unintentionally withdrawn in the upward direction.

18. A spindle as defined in claim 17, wherein said safety hook is pivotally mounted on said other of said plate and is normally held in a position in which it projects inwardly over said wharve flange and is adapted to be manually pivoted to another position in which it is removed from said wharve flange.

References Cited UNITED STATES PATENTS 1,882,144 10/1962 Hindle 57-88 3,116,591 1/1964 Miiller 57--88 3,122,875 3/1964 Swift et al. 5788 FOREIGN PATENTS 853,166 11/1960 Great Britain.

FRANK I. COHEN, Primary Examiner.

W. H. SCHROEDER, Assistant Examiner. 

